W3 Total Cache and Multi-DB - can't we all be friends?

I've seen several posts now on the forums where WPMU users are using/recommending W3 Total Cache for their WPMU installs over plugins like WP-Super-Cache in "half on" mode, for example.

I've been reading up on it, and I really like W3 Total Cache, because in addition to the regular object/page caching, it's set up for CDN and CSS/JS minification.

NOTE: My WPMU install is still pretty small (<100 blogs, but growing), and we're hosted on one of the pSek WPMU plans. And we've got multi-DB installed and working (16 DBs).

NOTE 2: We cannot use memcached or nginx while we're on pSek shared hosting.

Now, I'm trying to implement site-wide caching and a CDN (Amazon CloudFront w/ S3), but I've just learned that W3TC and Multi-DB don't work together, since they each require a 'db.php' file in /wp-content/


Has anyone gotten these two to work together? Any recommendations?